Fatty Acid Composition in Freeze-Dried Chinese Mitten Crabs (Eriocheir sinensis)

Lihong He, Feng Li, Junyong Tang

Department of Cell Biology, Medical College, Soochow University, Suzhou, China.

DOI: 10.4236/ojms.2012.23012                

Abstract

Freeze drying is reported to be the best method of dehydration. Live fresh Chinese mitten crabs (Eriocheir sinensis) were freeze dried. The moisture content, rehydration ratio, and fatty acid composition of freeze-dried crabs were analysed. The applicability of using freeze drying to process high-value E. sinensis, so as to prolong the time duration of their storage and marketing, were discussed. After lyophilisation, the average moisture content was 6%. The physical properties (shape, size, and colour) of the musculature and viscera were maintained well during freeze drying. The rehydration ratio was 2.15 when rehydrated for 30 min at room temperature. The levels of polyunsaturated fatty acids, especially eicosapentaenoic acid and docosahexaenoic acid, were higher in female freeze-dried crabs than in male crabs. After full rehydration, the fatty acid composition of freeze-dried crabs showed no significant differences to that of frozen crabs after thawing. In conclusion, freeze drying can well preserve the physical properties of the edible parts and fatty acid composition of the viscera in high-value E. sinensis. Rehydration has no destruction of the nutritional value regarding to the fatty acid composition. Therefore, freeze drying is a suitable technique for the processing of high-value E. sinensis.

Keywords

Eriocheir sinensis; Fatty Acid Composition; Freeze Drying; Frozen Storage; Rehydration Ratio; Viscera

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	China Society of Fisheries, “China Fisheries Statistic Yearbook 2004,” Bureau of Fisheries, Beijing, 2005.
[2]	Y. Q. Zeng, “New Technology in Chinese Mitten Crab Processing”, Scientific Fish Farming, Vol. 6, No. 6, 2003, pp. 60-61 (in Chinese).
[3]	C. Ratti, “Hot Air and Freeze-Drying of High-Value Foods: A Review,” Journal of Food Engineering, Vol. 49, No. 4, 2001, pp. 311-319. doi:10.1016/S0260-8774(00)00228-4
[4]	J. Folch, M. Lees and G. H. S. Stanley, “A Simple Method for the Isolation and Purification of Total Lipids from Animal Tissues,” Journal of Biological Chemistry, Vol. 266, No. 1, 1957, pp. 497-509.
[5]	W. R. Morrison and L. M. Smith, “Preparation of Fatty Acid Methyl Esters and Dimethyl Acetals from Lipids with Boron Trifluoride-Methanol,” Journal of Lipid Research, Vol. 5, 1964, pp. 600-608.
[6]	M. ?elik, C. Türeli, M. ?elik, Y. Yanar, E. ünal and K. Aygül, “Fatty Acid Composition of the Blue Crab (Call- inectes sapidu Athbun, 1896) in the North Eastern Mediterranean,” Food Chemistry, Vol. 88, No. 2, 2004, pp. 271-273. doi:10.1016/j.foodchem.2004.01.038
[7]	S. Cherif, F. Frikha, Y. Gargouri and N. Miled, “Fatty Acid Composition of Green Crab (Carcinus mediterraneus) from the Tunisian Mediterranean Coasts,” Food Chemistry, Vol. 111, No. 4, 2008, pp. 930-933. doi:10.1016/j.foodchem.2008.05.007
[8]	X. G. Wu, B. Zhou, Y. X. Cheng, C. S. Zeng, C. L. Wang and L. Feng, “Comparison of Gender Differences in Biochemical Composition and Nutritional Value of Various Edible Parts of the Blue Swimmer Crab,” Journal of Food Composition and Analysis, Vol. 23, No. 2, 2010, pp. 154-159. doi:10.1016/j.jfca.2009.08.007
[9]	FAO/WHO, “Fats and Oils in Human Nutrition,” Report of a Joint FAO/WHO Expert Consultation, FAO Food and Nutrition Paper 57, Rome, 1994, pp. 168.
[10]	D. W. Chen, M. Zhang and S. Shrestha, “Compositional Characteristics and Nutritional Quality of Chinese Mitten Crab (Eriocheir sinensis),” Food Chemistry, Vol. 103, No. 4, 2007, pp. 1343-1349. doi:10.1016/j.foodchem.2006.10.047
[11]	E. Kuley, F. ?Zogul, Y. ?Zogul and A. I. Olgunoglu, “Comparison of Fatty Acid and Proximate Compositions of the Body and Claw of Male and Female Blue Crabs (Callinectes sapidus) from Different Regions of the Mediterranean Coast,” International Journal of Food Sciences and Nutrition, Vol. 59, No. 7-8, 2008, pp. 573-580. doi:10.1080/09637480701451201
[12]	X. Yun, X. H. Han, S. Z. Nong and H. Yang, “Technological Condition of Vacuum Freeze-Drying in Stichopus japonicus,” Journal of Fishery Sciences of China, Vol. 13, No. 4, 2006, pp. 662-666 (in Chinese with English Abstract).
[13]	K. S. Jayaraman, D. K. D. Gupta and N. B. Rao, “Effect of Pretreatment with Salt and Sucrose on the Quality and Stability of Dehydrated Cauliflower,” International Journal of Food Science & Technology, Vol. 25, No. 1, 1990, pp. 47-60. doi:10.1111/j.1365-2621.1990.tb01058.x
[14]	C. Ratti, “Hot Air and Freeze-Drying of High-Value Foods: A Review,” Journal of Food Engineering, Vol. 49, No. 4, 2001, pp. 311-319. doi:10.1016/S0260-8774(00)00228-4
[15]	L. G. Marques, A. M. Silveira and J. T. Freire, “Freeze-Drying Characteristics of Tropical Fruits,” Drying Technology, Vol. 24, No. 4, 2006, pp. 457-463. doi:10.1080/07373930600611919
[16]	L. G. Marques, M. M. Prado and J. T. Freire, “Rehydration Characteristics of Freeze-Dried Tropical Fruits,” LWT —Food Science and Technology, Vol. 42, No. 7, 2009, pp. 1232-1237. doi:10.1016/j.lwt.2009.02.012
[17]	X. P. Ying, W. X. Yang and Y. P. Zhang, “Comparative Studies on Fatty Acid Composition of the Ovaries and Hepatopancreas at Different Physiological Stages of the Chinese Mitten Crab,” Aquaculture, Vol. 256, No. 1-4, 2006, pp. 617-623. doi:10.1016/j.aquaculture.2006.02.045
[18]	D. W. Chen and M. Zhang, “Analysis of Volatile Compounds in Chinese Mitten Crab (Eriocheir sinensis),” Food and Drug Analysis, Vol. 14, No. 3, 2006, pp. 76-82.